Borussia Dortmund have sacked head coach Nuri Sahin with the team out of the German Cup and struggling in the Bundesliga.
"Unfortunately, we have not managed to live up to Borussia Dortmund's sporting ambitions this season," Sahin said. "I wish this special club all the best."
The news comes after Dortmund lost 2-1 to Bologna in the Champions League on Tuesday. Dortmund had led but conceded two goals in two minutes to slump to a fourth straight defeat in all competitions.
"We value Nuri Sahin and his work very much," Dortmund sporting director Lars Ricken said. "We hoped for a long-term collaboration and until the end we had hoped that we could achieve a sporting turnaround together.
"After four defeats in a row, due to only one win in the last nine games and currently tenth in the Bundesliga table, we have unfortunately lost faith in being able to achieve our sporting goals in the current constellation. This decision hurts me personally, but it was unavoidable after the game in Bologna."
Sahin, who was appointed in June as Edin Terzić's replacement, was supposed to usher in a new era but the former Dortmund player's reign has proved short-lived with the team 10th in the league and looking unlikely to qualify for the Champions League next season.
Their Champions League form has proved to be something of a tonic for Sahin but Tuesday's defeat at Bologna prompted the club's management to move on from the former Real Madrid and Liverpool midfielder.
Terzić had led Dortmund on an improbable run to the Champions League final last season, where they were beaten 2-0 by Real Madrid, though the team's league form was less impressive as they scraped into this year's Champions League with a fifth-placed finish.
